Cutting honeycomb core to shape, particularly when complex three dimensional contours are involved, is difficult to accomplish in an economical fashion. First of all, the core must be cut without tearing, burning or deformation to the remaining core, thus, requiring the use of very sharp cutters. Quite often, knife edge cutters are used, but they dull quite quickly, requiring resharpening after only short periods. Since the cutter can only be resharpened a limited number of times, the use of such cutters can be expensive.
This has lead to the use of replaceable cutting edges as, for example, disclosed in U.S. Pat. No. 2,894,583 "Honeycomb Cutter" by D. Johnstad. Here a flange perpendicular to the axis of the shank is mounted at one end thereto. Thus, the entire cutting tool need not be removed from the machine when the cutting edge is dulled, for the ring shaped cutter can easily be replaced. However, such blades are made in relatively small numbers when compared to a typical circular saw blade and, thus are expensive. Also, the knife edge tends to heat up at high cutting rates, which limits cutting speed, less the core be burned. Furthermore, when this cutter is used to cut complex contours there is no means for eliminating the excess material which remains attached until completely cut through.
To eliminate this problem, a secondary cutter of a smaller diameter is often added behind the primary cutter for the simultaneous removal and shredding of the excess material. Such a device is disclosed in U.S. Pat. No. 4,620,821 "Cutting Device for Cutting Honeycomb Light Constructions" by D. Roth. This cutter has somewhat reduced cutting speed because of the secondary cutter design which grinds instead of shreds the removed core. Secondly, it is an expensive tool to manufacture. Also, it would be difficult to use when machining a three dimensional profile for the flat bottom of the primary cutter provides no place for debris from the cut to escape. This problem is eliminated in a bell shaped cutter disclosed in this patent, however this tool is also expensive to manufacture and sharpen because of its non-standard design.
Thus, it is a primary object of the subject invention to provide a honeycomb core cutting tool which can be used to machine three dimensional contours on honeycomb core.
It is another primary object of the subject invention to provide a honeycomb core cutting tool which simultaneously cuts the core and shreds the material being removed.
It is a further object of the subject invention to provide a honeycomb core cutting tool which is inexpensive to manufacture and maintain.
It is still further object of the subject invention to provide a honeycomb core cutting tool which uses ready available inexpensive commercially available cutters.